Transient receptor potential canonical 1 channel mediates the mechanical stress‑induced epithelial‑mesenchymal transition of human bronchial epithelial (16HBE) cells

Abstract

Airway remodeling is a central event in the pathology of chronic obstructive pulmonary disease (cOPd) that leads to airway narrowing and subsequently, to increased mechanical pressure. High mechanical pressure can exacerbate airway remodeling. Thus, a treatment regimen aimed at disrupting this high-pressure airway remodeling vicious cycle may improve the prognosis of patients with cOPd. Recent studies have demonstrated that mechanical stress induces lung epithelial-mesenchymal transition (EMT), which is commonly present in airway epithelial cells of patients with cOPd. As TRPc1 functions as a mechanosensitive channel that mediates non-selective cation entry in response to increased membrane stretch, the present study investigated the role of TRPc1 in the occurrence of EMT induced by mechanical stress. In the present study, the expression of TRPc1 in the bronchial epithelium was examined in vivo by immunohistochemistry. In vitro, human bronchial epithelial (16HBE) cells were subjected to mechanical stretching for up to 48 h, and TRPc1 expression was then examined by RT-qPcR and western blot analysis. In addition, TRPc1 receptor function was assessed by ca 2+ imaging and siRNA transfection. EMT was identified using immunofluorescence, western blot analysis and RT-qPcR. It was found that TRPc1 expression was upregulated in patients with cOPd and in 16HBE cells subjected to mechanical stretch. The mechanical stress-induced activation of TRPc1 in 16HBE cells increased the intracellular calcium concentration and subsequently decreased the expression of cytokeratin 8 and E-cadherin, and increased the expression of α-smooth muscle actin, indicating the occurrence of EMT. On the whole, the findings of the present study demonstrate that TRPc1 plays a key role in the occurrence of EMT in human lung epithelial cells in response to mechanical stretch; thus, this protein may serve as a novel therapeutic target for progressive airway remodeling in cOPd.

Breathing on Chip: Dynamic flow and stretch tune cellular composition and accelerate mucociliary maturation of airway epitheliumin vitro

“…These effects of moderate levels of mechanical cues are in contrast with the upregulation of inflammatory markers reported previously in the context of mechanical ventilation and excessive mechanical stretch and compression 9,18 . Contrary to studies using whole mount tissue 19 , undifferentiated primary cells 20 or cell lines 21,39,43 , our model may have captured phenotype-modulating, potentially even beneficial, effects of normal airflow and stretch by (i) using human primary cells from multiple human donors, (ii) allowing the basal cells to differentiate into a pseudostratified airway epithelium in the presence of mechanical stimulation, and (iii) applying mechanical stimulation over prolonged times, i.e. over 7 days compared to 24-48h 43,44 , in order to capture adaptive remodeling rather than an acute insult.…”

“…Contrary to studies using whole mount tissue 19 , undifferentiated primary cells 20 or cell lines 21,39,43 , our model may have captured phenotype-modulating, potentially even beneficial, effects of normal airflow and stretch by (i) using human primary cells from multiple human donors, (ii) allowing the basal cells to differentiate into a pseudostratified airway epithelium in the presence of mechanical stimulation, and (iii) applying mechanical stimulation over prolonged times, i.e. over 7 days compared to 24-48h 43,44 , in order to capture adaptive remodeling rather than an acute insult. The temporal dynamics, remodeling processes, and heterogeneous responses as observed in our study would likely have been missed in these previously used experimental designs.…”

Approach for Elucidating the Molecular Mechanism of Epithelial to Mesenchymal Transition in Fibrosis of Asthmatic Airway Remodeling Focusing on Cl− Channels

“…Several EMT studies focused on TRP channels and K + channels have been reported ( Table 2 ). Wang et al and Xu et al have revealed that TRP channels, which are non-selective cation channels that transmit not only Na + and K + , but also Ca 2+ and Mg 2+ , are associated with EMT in asthma and chronic obstructive pulmonary disease [ 91 , 92 , 93 ]. TRP channels are widely recognized to respond to temperature, nociceptive stimuli, touch, osmotic pressure, pheromones, and other stimuli from within and outside the cell [ 94 ].…”

Transient Receptor Potential Channels in the Epithelial-to-Mesenchymal Transition

“…Furthermore, the application of cigarette smoke extract to human bronchial epithelial cells (16HBE) resulted in the induction of EMT. This was evidenced by increased vimentin expression and decreased E-cadherin expression, a phenomenon that was exacerbated by overexpression of TRPC1 [ 47 ]. Recently, a similar finding was observed by subjecting 16HBE cells to cyclic mechanical stretching to induce EMT, followed by both increased molecular and functional expression of TRPC1.…”